CSSStyleSheet

The CSSStyleSheet interface represents a single CSS style sheet. It inherits properties and methods from its parent, StyleSheet.

A style sheet consists of rules (en-US), such as style rules (en-US) ("h1,h2 { font-size: 16pt }"), various at-rules (@import, @media, ...), etc. This interface lets you inspect and modify the list of rules in the stylesheet.

See the Notes section for the various ways a CSSStyleSheet object can be obtained.

Properties

Inherits properties from its parent, StyleSheet.

CSSStyleSheet.cssRules (en-US)
Returns a live CSSRuleList (en-US), listing the CSSRule (en-US) objects in the style sheet.
This is normally used to access individual rules like this:
   styleSheet.cssRules[i] // where i = 0..cssRules.length-1
To add or remove items in cssRules, use the CSSStyleSheet's deleteRule() and insertRule() methods, described below.
CSSStyleSheet.ownerRule (en-US)
If this style sheet is imported into the document using an @import rule, the ownerRule property will return that CSSImportRule (en-US), otherwise it returns null.

Methods

Inherits methods from its parent, Stylesheet.

CSSStyleSheet.deleteRule() (en-US)
Deletes a rule at the specified position from the style sheet.
CSSStyleSheet.insertRule() (en-US)
Inserts a new rule at the specified position in the style sheet, given the textual representation of the rule.

Notes

In some browsers, if a stylesheet is loaded from a different domain, calling cssRules results in SecurityError.

A stylesheet is associated with at most one Document, which it applies to (unless disabled (en-US)). A list of CSSStyleSheet objects for a given document can be obtained using the document.styleSheets property. A specific style sheet can also be accessed from its owner object (Node or CSSImportRule), if any.

A CSSStyleSheet object is created and inserted into the document's styleSheets list automatically by the browser, when a style sheet is loaded for a document. As the document.styleSheets list cannot be modified directly, there's no useful way to create a new CSSStyleSheet object manually (although Constructable Stylesheet Objects is coming to the web platform soon and is already supported in Blink). To create a new stylesheet, insert a <style> or <link> element into the document.

A (possibly incomplete) list of ways a style sheet can be associated with a document follows:

Reason for the style sheet to be associated with the document Appears in document.
styleSheets
list
Getting the owner element/rule given the style sheet object The interface for the owner object Getting the CSSStyleSheet object from the owner
<style> and <link> elements in the document Yes .ownerNode (en-US) HTMLLinkElement (en-US),
HTMLStyleElement (en-US),
or SVGStyleElement (en-US)
.sheet
CSS @import rule in other style sheets applied to the document Yes .ownerRule (en-US) CSSImportRule (en-US) .styleSheet (en-US)
<?xml-stylesheet ?> processing instruction in the (non-HTML) document Yes .ownerNode (en-US) ProcessingInstruction (en-US) .sheet
HTTP Link Header Yes N/A N/A N/A
User agent (default) style sheets No N/A N/A N/A

Specifications

Specification Status Comment
CSS Object Model (CSSOM)
The definition of 'CSSStyleSheet' in that specification.
Working Draft  
Document Object Model (DOM) Level 2 Style Specification
The definition of 'CSSStyleSheet' in that specification.
Obsolete Initial definition

Browser compatibility

BCD tables only load in the browser

See also